A substrate of, for example, a hard disc, is scrubbed after steps of grinding, polishing, sputtering and plating, etc. On the other hand, the cleaning of such as wafer includes a plurality of cleaning steps and a corresponding number of drying steps.
In a known scrubbing device, the scrubbing step is performed by dipping a carrier (or a tray), on which a plurality of discs are vertically mounted, in a tab filled with cleaning agent and applying ultra sonic waves thereto. In such a case, the cleaned discs are dried by transporting the carrier (or tray) into a drying chamber.
On the other hand, JP2001-96245A discloses a cleaning device, which includes a conveyer covering a shower tab, a cleaning agent tab, an ultrasonic wave tab and a pure water tab, respectively, to convey discs from the shower tab to the pure water tab, sequentially.
Further, JP2001-29905A discloses a technique for cleaning discs, in which a plurality of radially arranged cleaning chambers, each including a brush cleaning chamber (for scrubbing the discs using brushes), a jet cleaning chamber and a shower cleaning chamber are used. In this technique, the discs are arranged vertically on a turntable and one of the cleaning chambers is selectively activated corresponding to the degree of contamination of the discs by rotating the turntable.
JP-H11-129349A discloses a technique for scrubbing a number of discs simultaneously, in which a number of circular brush plates are arranged on a shaft at equal intervals as a rotary brush and a portion of each of the discs is caught between adjacent circular brush plates.
Incidentally, in the brush cleaning, it is typical that the cleaning is performed by using porous elastic sponge members (referred to as “sponge members”, hereinafter) instead of the usual brushes and rotating discs having surfaces in contact with the sponge members. In this specification, the sponge member is included in the concept of the brush.
Nowadays, the hard disc is used in the fields of such as automobile appliances, home appliances and audio appliances and the hard disc drive devices for 2.5 inch to 1.8 inch or less than 1.0 inch discs are provided within various appliances and there is a tendency of reduction of size of the hard disc device. Further, the unit cost of the hard disc drive device itself is lowered. Therefore, manufacturers of hard disc devices require the fabrication of a large quantity of low cost hard disc drives.
For this reason, a disc cleaning device capable of cleaning a large quantity of discs simultaneously is required. However, although the disc cleaning device mentioned above can perform batch processing, the scrubbing portion thereof is only of the sheet-fed type in which the discs are cleaned individually. Therefore, in view of the request of simultaneous cleaning of 2.5 inch discs or smaller, the prior art sheet-fed type disc cleaning device is not appropriate.
Further, since the rotary brush used in the scrubbing type cleaning has to contact one of opposite surfaces of the disc, it is usual that independent rotary shafts for the discs and the rotary brushes are necessary, so that the size of the cleaning machine is increased. In addition to this, since the rotary shaft is inserted into centers of the discs, it is impossible to sufficiently clean internal portions of the discs.
Although the technique described in JP-H11-129349A performs the scrubbing cleaning of the discs by using the circular brush plates having a large diameter and arranged on the shaft at equal intervals, the independent rotary shafts are required for the discs and the rotary brushes, respectively. Further, since it is necessary to provide the large circular brush plates independently and to externally contact top end portions of the large circular brush plates with the surfaces of the discs, the size of the cleaning machine is increased. Therefore, the machine is not suitable to clean compact discs.